Turbine generators are known in the art for producing electrical power and are examplified by U.S. Pat. Nos. 3,203,191, 3,383,873, 4,334,902 and 4,808,837. A submerged turbine power generator is disclosed in U.S. Pat. No. 4,740,711 wherein the turbine generator is constructed in line on a single shaft in a fluid pipeline operative from the steam or gaseous fluid conveyed in the pipeline for operating the turbine and thereby the electric power generator and utilizing the pipeline flow for cooling the power generator. This disclosed patent does not address the practical problems and the solutions necessary for producing an operative system including the well known turbine thrust problem.
A related known prior art is the submersible pumps for handling cryogenic fluids such as liquefied natural gas, liquid ethylene and similar cold liquids. These types of submersible pumps are commercially available from EBARA International through its Cryodynamics Division of Sparks, Nev. The EBARA submersible pump and thrust equalizing mechanism is described in detail in the publication "World Pumps" for January 1994 on pages 23-25 by G. Louis Weisser of the Cryodynamics division of EBARA International. The disclosed pump is a centrifugal pump that is motor driven and exhibits the hydraulic thrust problem on the impeller. The Weisser publication discloses a unique solution to the thrust problem through the use of a thrust equalizing mechanism (TEM) operative through the forces generated by the pumped fluids to cause a shaft assembly to axially move bidirectionally over a limited distance to offset the thrust continuously through self-adjustment. The Weisser thrust equalizing mechanism provides the means for balancing the axial forces on the thrust bearing whereby the product lubricated thrust bearing operates at essentially "zero" thrust load over the entire usable flow range.
The existence of the thrust forces is known to be a big problem in all turbines and various solutions have been attempted. One such solution is disclosed in U.S. Pat. No. 4,362,020 for a Hermetic Turbine Generator. The turbine shaft is arranged in a vertical orientation with the turbine and electric power generator mounted on a single shaft that is supported on a hydrodynamic fluid film bearing generated from the process fluid. A complicated mechanism is disclosed to eliminate the thrust problem through the use of a thrust runner and bearing plates. This is not the thrust equalizing mechanism or the equivalent disclosed in the above identified publication of Weisser.
Although the Weisser thrust equalizing mechanism has been used and known in the art for use with submersible pumps no use of this elegant solution to the thrust forces in a hydraulic turbine are presently known.